APA
Gilpin A., . (1999). Environmental economics. Chichester, England: John Wiley.
Chicago
Gilpin Alan, . 1999. Environmental economics. Chichester, England: John Wiley.
Harvard
Gilpin A., . (1999). Environmental economics. Chichester, England: John Wiley.
MLA
Gilpin Alan, . Environmental economics. Chichester, England: John Wiley. 1999.